This invention relates to the management of water flows through dams, and in particular to an apparatus that enables dam operators to discharge through the dam a variable blend of water from around the surface and the lower depths of the reservoir.
Dam operators are often required to manage water flow through hydroelectric dams so that the discharge from the turbines is of a desired temperature, oxygen content, or other criteria. These requirements can be directed toward fish passage through the dam or fish habitat requirements below the dam, e.g. water temperature, oxygen content, etc. Dam operators attempt to meet these requirements by introducing into the turbine intakes, or turbine bypass intakes, or spilling, water from various depths in the impoundment. In some cases, the intakes are several hundred feet below the water surface. Various structures have been proposed for this purpose, but so far none are satisfactory due to either their high cost, or the technical difficulties in building, operating or maintaining the structures, or the power generation revenue lost from excessive spilling.